Telephone-exchange system



July 5 1927. 2

w. G. BLAUVELT TELEPHONE EXCHANGE SYSTEM Filed May '7I 1926 2 Sheets-Sheet 2 1407/0/72 57am/6M Cil Patented July 5, 1927.

sturen STATES Parana carica WILLIAIVI G. BLA'UVELT, OF NEW YORK, N'. 'Y., .ASSGNGR TO AMERCAN TELEPHONE .AND TELEGRAPH COMPANY, A COEPORATON OF NEW YORK.

TELEPHONE-EXCHANGE sYsTnM.

Application filed May 7, 1926. Serial No. 107,473.

This invention relates to telephone eX- change systems and more particularly to systems in which connections are established through the use of automatic switches.

The invention is in the nature of an improvement on the system disclosed in my application Serial No. 680,029]` tiled December 11, 1923, Patent No. 1,577,513, granted March 23, 1926, which application covers a selector switch arrangement in which a plurality of individual switches are operated by means of a common control and driving mechanism. Two sequence switches are employed in that system for associating the individual switches with the common apparatus. L A

The principal object of the present invention is to simplify and improve the control and'operation of automatic switches.

According to one aspect of the invention means are provided for making the group selection and trunk hunting operations continuous. According to another aspect of the invention the system is arranged for controlling the selector driving apparatus vby means of a relay which is held operated continuously under the control of the sender during selections and under the control ot the sleeve oi the busy outgoing trunks during trunk hunting.

These and other objects and aspects of the invention will be more apparent from a` consideration of the following descrip-y tion in connection with the drawings and appended claims.

1n the drawings, Figure 1 shows two trunk circuits each terminating in a selector switch and a common brush rod for operating said switches.

Fig. 2 shows the apparatus common to all the trunk circuits served by the brush rod.

Fig. 8 shows the manner otarranffing Figs. 1 and 2 to disclose the invention.

The selector switch ot' Fig. 1 is yot the type shown and disclosed in U. S. patent to E. B. Craft and J. ll.. Reynolds, No. 1,123,696, issued January 5, 1915. As in the case of my above mentioned patent a number oi' trunk circuits, usually tive, are served by a common brush rod and certain common apparatus. Each trunk terminates in a brush set, normally disconnected from the common brush rod. ln the present case, however, the brush set of the selected trunk is associated with the brush rod by an individual magnet and apparatus which is described and claimed in the application Serial No. 105,670, of l-l. W. Goiled April 30, 1926.

1n general, upon the initiation of a call by a subscriber a connection will be eX- tended by any lwell known means such as those disclosed in U. S.k Patent No. 1,395,- 977, issued November 1, 1921, to F. A. Stearn, et al., to the terminals leading t0 one ot the trunks served by brush rod 100.

A relay individual to the trunk is operated causing the closure of a circuit which eX- tends serially through the trunks Vserved. by brush rod 100 it they'areidle, and if the brushrod is tree to serve the'call. This i circuit causes the association of thebrush sety with the common brush rod and also initiatcs the group selecting operation. .Relay 200 controls the operation of group selection and also causesthe operation oit relay 201 which controls the brush rod and is held to the sleeve or" the outgoing trunk if that trunk is busy.y As soon as an idle trunk is found, relay 201 releases opening the circuit of the brush set magnet and leaving the brushes engaging the terminals of an idle trunk. The release of relay 201 also causes the Vclosure of the circuit of the downdrive magnet and the restoration of the brushv rod. TWhen av brush set is to ybe restored to non mal, the brush rod is moved tothe topmost position, where the brushmagnet is energized and inV moving down past the brush set, associates it with the brush rod and restores it to normal.

lThe detailed operation otl these circuits is as follows: Assuming that a call has been initiated by a subscriber at substation 101, the connection will be extended as previously indicated to terminals 102, 103 and 104. A circuit is thereupon established fromk battery through the right winding of relay 10Q, normal contact 106 controlled by the brush set, over the tip conductor of the trunk, terminal 102, lto the sender, back to terminal 103` and the ring conductor of the trunk, normal contact 107 to ground. Relay 105 operates-and prepares a locking circuit ior 'itself through its lett winding and lett rontvcontact, on normal contact 108 as soon as closed, sleeve terminal 104 to ground in the previous selector. v The presmal Contact 141 and the sleeve terminal oir'.

the second trunk, and over similar paths to thesleeves `ol" other trunks oit the group, rendering them nonselectable While the coin- 'mon apparatus is busy with one of tile trunks. Relay 105, in operating, closes a circuit from ground over its outer right trontcontact, normal contact 109, right Winding of relay 110, back contact o1 relay '202, resistance 203 to battery. Relay 110 operates in this circuit and closes a circuit trom ground through its left Winding'` and innerlett trent Contact, inner left baclr contact of relay 150, Winding o1 relay 202, re-

:sistance 203 to battery, Relay202 operates in this circuit and opens the original energizing circuit of relay 110. The series character of the locking circuit of relays 110, 150, etc. creates a preference in favor of the trunk Whose relay is nearer the common apparatus ink the series, should tWo calls reach the group of trunks simultaneously. The energizing circuit of relay 110 shunts the -Winding ot relay 202 suiticiently to pre- -'vent rela7 202 from oaeratino' until rela 710 has completely attracted its armatures. The operation ot' relay 202 also opens the energizing circuits or all relays corresponding to relay 110 in the group thus preventing the seizure oit the common apparatus as long as it is in use. Relay 110 also closes a circuit 'from battery through the Winding of relay 111, inner lett front contact or" relay 110 to ground. Relay 111 in operating opens the tip and ring conductors and connects them through to the common apparatus i'or` the purpose or" brush selection. rllhe ring conductor connectetd 'to ground on the inner right front contact olf relay 111. The tip conductor is connected over the outer right front Contact oi:` relay 111, front contact o't relay 202, bottom normal contact 112, Winding of relay 200 to battery. The tip and ringr conductors are connected through the stepping relay oia the sender in the usual manner. Relay 200 operates and locls over its lett liront Contact, to its energizing circuit independently ot the bottom normal Contact 112. Relay 200 in operating also lcloses a circuit irom battery over-its lett iront Contact and inner right front Contact, to commutator segment 114. lt also closes a circuity from battery through the right Winding oi' relay 201 to ground at the outer right front contact et relay 200.

Relay 201 operates and prepares two locking circuits for itself, one from battery over the left back contact et relay 201, lei't winding and lett front Contact oit relay 201. inner lett iront Contact ot relay 111 to sleeve brush 113, the other 'from battery, through its right Winding andinner right :tront contact, commutator strip 121, brush 128 to ground, The operation o1 relay 201 closes a circuit from battery through the Winding` of magnet 11'?, right front Contact oii relay 110, rig it baci; contact ot relay 150, to ground at the outer right front Contact o1E relay 201, causing an engagement With its armature which is attached to brush set 130 'whereby the brush set moves with the magnet. Relay 201 in operating also closes a circuit from battery, Winding et relay 205, top contact 115, right baclr contact of relay 204, middle right front contact ot relay 201 to ground. Relay 205 operates in this circuit and closes a circuit from battery through the Windfng ot updrive magnet 116, right front Contact ot relay 205 to ground. Brush rod and brush set 130 are thereupon moved upward under the control ot the updrive magnet 116.

The upward movement oi the brush setraises rod 121, opening triey normal contact set and closing the group oi.t ott-normal contacts. lt should be noted VthaiI the contacts 106 and 108 are so arranged that oil-normal Contact 108 will be closed betere normal Contact 106 is broken, thus closing the holding circuit through the le'l't. Winding of relay 105, before the original energizing circuit through the right Winding or that relay is opened, holding relay operated under the control of the sleeve of the district selector.

is the brush moves upward the coinmutator brush 122, which moves with the rod 100, mal-:es Contact with conducting segments of commutatoristrip` 114. Ground over brush 122 thus serves to complete intermittently the holding circuit for relay 200 and shunt the stepping` relay ot the sender in the usual manner lVhen the stepping relay has been shunted enough times to satisiiy the setting of the sender, the fundamental circuit is opened and relay 200 releases as soon as commutator brush 122 engages the next insulating segment ot strip 114. However.y the updrive magnet is under the control oit relay 201 and, should the iirst outgoing trunk in the selected group prove busy, relay 201 will beheld operated in the previously traced holding circuitl over the sleeve of the outgoing trunk. vT he brush rod will continue to move upward until, due to the encountering ot an idle trunk this holding circuit of relay 201 is opened. The second holding circuit over commutator strip .127 is effective until the brushes are centered, after which relay 201 releases. The release of relay 201 opens the circuit oit net.

the brush .set magnet 117 and leaves the brushes engaging the idle outgoing trunk. 1t immediately connects ground over its back contact, inneiI left front contact of relay 111 to sleeve brush 1123, making the outgoing trunk busy to other selector switches. ylt also opens the circuit of relay 205, releasing that relay which in turn opens the circuit of the updrive magnet and brings the brush rod to rest.

The release o1' relay 205 also closes a circuit from battery through the winding of relay 204, oi normal contact 123, back contact of relay 205 to ground. Relay 20Llin operating removes battery Y:rom the' holding circuit of relay 201, thus further insuring the release of relay 201 and the brush maglt also closes a circuit through downdrive magnetf124 to ground at the left Vfront contact of relay 204.' The downdrive magnet nowrestores brush rod to normal position. is the brush rod approaches its normal position a circuit is closed from battery through the winding of relay 202, outer right i'ront Contact of relay 204:, normal commutator segment 125, brush 126 to ground. rlhis circuit is in shunt of that through the left winding of relay V110 and releases relay 110 which in turn releases relay 111. The release of relay v111 connects the tip and ring conductors through to the brushes 120 and 119, after which subsequent selections f are completed. The` release of relay 111 also closes ground over the inner right front Contact ol' relay 105, left normal contact of relay 111 to sleeve brush 113 to hold the outgoing trunk busy when the common `apparatus is in use with other trunks. When the brush rod reaches normal theoperating cir- 1 Relay immediately closes ground over its left back contact, oltnormal contact 108 to the ksleeve terminal 101 to prevent the false selection of thistrunk while it is being restored. The release of relay 105 also closes ground over oH-normal contact 127 right winding of relay 110, inner back contact of relay V202, resistance 203 to battery. Relay 110 operates and closes the operating circuits of relays 111 and 202 as before. It also closes a circuit from ground at the outer right back contact of relay 105, outermost ae'l't contact or relay 110, right back contact olf relay 204e, top contact 115, winding or" relay 205 to battery. Relay 205 operates as before and energizes the updrive magnet 116. Brush rod 100 is driven, under the control of magnet 116 to its'topmost posi- 11G and bringing the brush rod to rest.v

lilith the brush rod in this position, a circuit is closed from battery, through .the right n'inding of relay 201, top commutator segment 131, brush 128 to ground. Relay201 operates. The release or relay 205 closes the previously traced circuit or' relay 201 which in turn energizes the downdrive. magnet 12a. elay 2011 also closes a locking` circuit 'iioi' relay 201 extending from battery, through the right winding and inner right front contact of relay 201, inner light front co .act or relay 204;, :niddle right front contactcl relay 201-to ground. Relay 201 closes the circuit of the brush magnet 117 as before. Y

Under the control or downdrive magnet 124 the brush rod 100 is lowered. With magnet 11i' energized, as the magnet comes opposite the brush set, magnet 117 attracts the armature attachedto brush set 130` and lowers the brush setwith the brush rod. The further restorationoi the commonap paratus is the saine as described. VThe restoration ci' the brush set also closes the group oi norn'ial contacts individual to that trunl; and opens the onnorm'alf. contacts. rlie opening of Contact 108removes Vthe busy condition rromsleeve terminal 104. 'lhe closure of contacts 10G and 107 prepares the trunk Jor use in connection with a sub,- sequent call. lt should benoted that whenever the brush rod moves upward, ground is connected from thebrush rod olf-normal contact 132 to the sleeve lterminals of all the trunks or the group, preventing the selection olone ofl the trunks whileV the brush rod is busy. f y

Should no idle trunk be foundv in the selected group, the ungrounded condition of the sleeve of the overflow terminals releases relay 201. Therbrushset remainson the overflow terminals wl ile thebrush rod is restored in the manner above described. The usual overflow signal` is given to the calling subscriber who restores his receiver and releases the connection. The restoration of the trunk is the same as from a successful call.

l/Vhat is claimed is:

1. In atelephone exchange system, a selector switch, a register sender, a plurality of groups or trunks having terminals and accessible through said selector switch, means for identifying the sleeve terminals or busy trunlraand means associated with said selector switch for causing the operation or said.y switch to select a particular group ot trunks and to find an idle trunk in said group, said means rbeing held operated continuously during the operation of said switch, under the control of said sender during group selection and under the con- Cil trol ot the sleeve terminal of busy trunks during trunk hunting.

Q. In a telephoneexchange system, brush sets, a group of trunks each terminating in a brush set, a brush rod, means for associating each ot' said brush sets with said brush rod, a plurality ot groups of outgoing trunks accessible to each brush set, means t'or identifying busy trunks, apparatus common to said trunks tor controlling the extension of a connection over one ot' said trunks, and means in said common apparatus etlleetive When said common apparatus is taken for use With a particular trunk to associate the proper brush set with said brush rod and to operate said brush rod to select a particular group of outgoing trunks accessible to said brush set and to iind an idle trunk in said group, said means being held operated continuously during the operation ot said brush rod.

3. In a telephone exchange system, brush sets, a group ot trunks each terminating in a brush set,a brush rod, means tor associating each ot said brush sets with said brush rod, a plurality ot groups ot outgoing trunks accessible to each brush set, mea-ns for identifying busy trunks, apparatus common to said trunks i'or controlling the eX- tension of a connection over one ot said trunks, and means in said common apparatus effective when said common apparatus is taken for use with a particular' trunk to associate the proper brush set with said brush rod and to operate said brush rod to select a particular group of outgoing trunks accessible to said brush set and to find an idle trunk in said group, said means being held operated continuously during the operation ot' said brush rod, and immediately released When an idle trunk is found to release said brush set and to leave said brush set in connection with said idle trunk.

Ll. In a telephone exchange system, brush sets, a group ot trunks each terminating in a brush set, a brush rod, means tor associating each ot said brush sets with said brush rod, a plurality ot groups oi outgoing trunks accessible to each brush set, means for identifying the sleeve terminals of busy outgoing trunks, a register sender, apparatus common to said trunks tor controlling the extension of a connection over any one ot said trunks, and means in said common apparatus effective when said common apparatus is taken for use With a particular trunk to associate the proper brush set with saidbrush rod and to operate said brush rod to select a particular group of outgoing trunks accessible to said brush set and to lind an idle trunk in said group, said means being held operated continuously during the operation oi said brush rod under the cont-rol of said sender during group' selection and under the control otl the sleeve terminal of busy outgoing' trunks during trunk hunting.

5. In a telephone exchange system, brush sets, a group ont trunks each terminating in a brush set, a brush rod, means for associating each ot said brush sets with said brush rod, a plurality ot groups of outgoing trunks accessible to each brush set, means tor identifying the sleeve terminals ot' busy outgoing trunks, a register sender, apparatus common to said trunks tor controlling the extension of a connect-ion over any one ot said trunks, means in said common apparatus effective when said common apparatus is taken for use with a particular trunk to associate the proper brush set with said brush rod and to operate said brush rod to select a particular group of outgoing trunks accessible to said brush set and to yiind an idle trunk in said group, said means WILLIAM Gr. ,BLAUVEIII 

